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Funding for this trial has been provided in full or in part by Cystic Fibrosis Foundation Therapeutics, Inc.

Study Phase:

2

Recruitment Status:

Trial Completed

Study Drug(s):

Kalydeco

Number of Participants Being Recruited:

80

Single / Multi-Center:

Multi-Center

STUDY BACKGROUND INFORMATION:

Cystic Fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The CFTR protein is located on the cell membrane of the airways and sweat ducts. It is a chloride ion channel responsible for aiding in the regulation of salt and water absorption and secretion in tissues. Potentiators are pharmacological agents that increase the chloride ion transport properties of the channel. The increase in CFTR chloride ion channel opening may prevent hyperabsorption of water in the airway tissues, allowing for more favorable maintenance of airway hydration in people with CF.

This study looked at the effectiveness of VX-770 in people with CF and the G551D mutation by evaluating an absolute change from baseline in % predicted FEV1 through week 24 and safety over a longer treatment period than previously studied.

ELIGIBILITY

Age:

>= 12 Years

FEV1:

40 - 90 Percent Predicted

P. aeruginosa status:

Not applicable

B. cepacia status:

Not applicable

Other Primary Eligibility Requirements:

To be eligible, subjects must have the G551D-CFTR mutation in at least 1 allele (any known or unknown mutations allowed in second allele).

Note: Detailed eligibility criteria information may be available on clinicaltrials.gov. If a specific
trial listing for this trial is available, a link to the specific clinicaltrials.gov listing will be present in the "More Information" section below.

This Phase 3 study evaluated safety and efficacy of VX-770 in 161 CF subjects with at least one G551D-CFTR allele. Subjects received either 150 mg VX-770 or placebo twice daily for 48 weeks. The study met the primary endpoint of mean absolute change from baseline compared to placebo in FEV1 percent predicted through week 24. A mean absolute improvement from baseline compared to placebo of 10.6 percent was achieved (p<0.0001) and sustained through 48 weeks (10.5%; p<0.0001).

Secondary Efficacy:

Significant improvement in all key secondary endpoints (fewer pulmonary exacerbations, weight gain, reduction in sweat chloride) were also observed through week 48 in subjects who received VX-770. Improvements in CFQ-R respiratory domain were also reported.

Safety:

The incidence of adverse events through week 48 was similar in the two groups. Discontinuation of study drug through week 48 due to adverse events was less frequent in the VX-770 treatment group (1 percent compared to 5 percent in the placebo group).